Sutures are used to sew tissue together, and thereby close tissue openings, cuts or incisions during or after any of a very wide variety of medical procedures. Typically, the surgeon manually ties together a suture pair to close the opening, however, automatic suture tying systems have also been developed.
There are a number of disadvantages of knotting sutures together to secure tissues to one another. For example, manual knot tying requires considerable dexterity. Also, manual knot tying can take considerable time. Knot tying is further complicated by the fact that surgical sutures have low friction surfaces. Therefore, it is typically necessary for a surgeon to include many “throws” when tying the knot. This multiple-throw problem occurs even if an automatic knot tying device is used. Unfortunately, as the number of loops or “throws” incorporated into the knot increase, the knot becomes increasingly large and bulky. Moreover, the surgeon typically needs to handle strands of adequate suture length prior to commencing manual knot tying. Thus, manual knot tying requires considerable space both in which to view, and to perform, the actual suture knot tying. Therefore, knot tying is particularly difficult in areas of limited available space or access, for example, at the back of the patient's heart during a coronary artery bypass graft (CABG) operation. Manually tied knots often lock prior to reaching the intended amount of tension to be applied to the tissue. Furthermore, tissues are typically secured together by a pair of sutures wherein each of the sutures in the pair pass through both of the tissues which are secured together by tying off the suture pair. It would instead be advantageous to provide a system which is adapted to secure together two tissues, but uses only a single strand of suture.